Images from the National Geophysical Data Center
Image from the USGS
The southwest coast of North America is a classic transform boundary. An extensive fault system (the San Andreas) marks the boundary between the adjacent ocean and continental plates. Narrow, relatively low and non-volcanic mountain ranges are close to the coast of southern California and Baja California.
Off the coasts of Washington, Oregon and British Columbia, a different type of active plate boundary exists. Volcanic mountains and an offshore trench make this what type of boundary?
The following images show topography and its relation to the plate boundary.
Images from the National Geophysical Data Center
Image from the USGS